A Scalable Secure Multicast System

Multicast is an efficient way to distribute data to multiple receivers simultaneously. However, security, scalability, and group management issues still prevent the wide deployment of multicast data transmission. In this paper, we will present a Scalable Secure Multicast System. To provide scalability, the system has a hierarchical structure. The system ensures Perfect Forward Secrecy and Perfect Backward Secrecy by updating keys for the sub-tree that can cover the group membership changes. We will present two schemes that apply this system. One is a multicast data encryption scheme that transforms multicast data for given sub-groups using Proxy Encryption. It guarantees that only valid members in a sub-tree can decrypt transformed data. Another is a key distribution scheme that uses Proxy Encryption to protect re-keying messages, and it ensures that only valid receivers in a sub-tree can obtain updated keys. This system also follows most of the guidelines described in RFC 3740, so that the system is compatible with standards and can be used in the Internet.